package org.nnsoft.guice.rocoto.converters;

/*
 *    Copyright 2009-2012 The 99 Software Foundation
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

import java.util.BitSet;
import java.util.StringTokenizer;

import com.google.inject.ProvisionException;
import com.google.inject.TypeLiteral;

/**
 * Converter implementation for {@code java.util.UUID}.
 */
public final class BitSetConverter
    extends AbstractConverter<BitSet>
{

    private static final String DEFAULT_SEPARATOR = ",";

    private static final int CHAR_LENGTH = 1;

    /**
     * {@inheritDoc}
     */
    public Object convert( String value, TypeLiteral<?> toType )
    {
        BitSet bitSet = new BitSet();

        int currentIndex = 0;
        StringTokenizer tokenizer = new StringTokenizer( value, DEFAULT_SEPARATOR );
        while ( tokenizer.hasMoreTokens() )
        {
            String current = tokenizer.nextToken().trim();

            if ( current.length() == 0 )
            {
                throw new ProvisionException( "Input '" + value
                    + "' is not a valid java.util.BitSet, fragment at position " + currentIndex + " is empty" );
            }

            if ( CHAR_LENGTH == current.length() && !Character.isDigit( current.charAt( 0 ) ) )
            {
                bitSet.set( current.charAt( 0 ) );
            }
            else
            {
                for ( int i = 0; i < current.length(); i++ )
                {
                    if ( !Character.isDigit( current.charAt( i ) ) )
                    {
                        throw new ProvisionException( "Input '"
                                                      + value
                                                      + "' is not a valid java.util.BitSet, fragment '"
                                                      + current
                                                      + "' at position "
                                                      + currentIndex
                                                      + " is not a valid integer" );
                    }
                }
                bitSet.set( Integer.parseInt( current ) );
            }

            currentIndex++;
        }

        return bitSet;
    }

}
